ATLANTA (AP) - Students evacuated two Georgia Tech dorms Monday morning after a janitor found a chemical-filled bottle on a campus courtyard that exploded, police said.

At least two more bottles were found and detonated by Atlanta police.

Suspects could be charged with making terroristic threats and may face federal charges, said Sylvia Abernathy, an Atlanta Police spokeswoman.

''Police are taking this seriously,'' she said.

About 100 students were evacuated from Cloudman and Glenn residence halls after the janitor found the suspicious bottle at 8:45 a.m., said spokeswoman Amelia Gambino.

''They're investigating this as a very serious offense _ we're looking to find who produced these and distributed these devices,'' Gambino said. ''Everybody is safe. We'd like parents to know that students weren't injured.''

The janitor was picking up trash in the courtyard when he pulled out the bottle from bushes. The bottle exploded and the janitor was taken to a local medical clinic for evaluation but suffered no serious injuries, Gambino said.

Police still are working to determine what chemicals were in the bottles. The incident prompted authorities to contact the Georgia Department of Homeland Security.